I looked at your pix and my guess on the last one is that they're trying to say you imitated Amy Brown...not that the styles look close but the composition of the piece. And again that makes no sense because there's no copyright for composition.
This is all just so very stupid. And yet it explains to me why my artist friend Aimee's gallery suddenly went from twenty or thirty pieces down to just five. I love her work but I can see them hitting her up for the white space and the 'non-genre' stuff because she's not all fairy and knights (she's werewolves, and sometimes DiscWorld, and a whole lot of other ideas the imagination can come up with).
Elfwood is now dead to me.